1. Field of the Invention
The present invention relates to an adjusting method of button attaching apparatus for attaching a button to a fabric and adjusting jig used in the adjusting method.
2. Description of Related Art
Conventionally, a button attaching apparatus for automating operation for attaching button etc. such as snap fastener has been utilized (see Japanese Utility Model Publication No. Hei 3-1447).
In such button attaching apparatus, one and the other of a pair of button components (button and backing member) are respectively attached to a pair of dies (first die and second die) sandwiching the fabric, the dies being pressed to caulk and engage the button and the backing member with each other sandwiching the fabric, thereby attaching the button to the fabric.
In the button attaching apparatus, a pair of holders capable of attaching and detaching the respective dies are provided so that a die corresponding to the button to be attached can be selectably used. A drive mechanism is provided on one or both of the respective holders to advance and retract the one or both of the dies in a direction for the dies to be moved toward and away from each other (along an advancement-retraction axis line), so that the respective dies are pressed or separated for attaching the button by caulking.
A cushion structure using spring etc. is provided to a part of the holder or the drive mechanism for absorbing fluctuation of the thickness of the fabric to a degree. In other words, even when the thick fabric is used, the die is pushed against, for instance, biasing force of a spring, so that generation of excessive pressing force between the dies can be prevented. Such cushion mechanism may be provided on either one of the dies or, alternatively, on both of the dies. When the cushion mechanism is provided on one of the dies, either of the advanceable holder and a stationary holder may be provided with the cushion mechanism. Further, various arrangements such as installing the cushion mechanism in the holder, supporting the holder in a cushioning manner against the drive mechanism and disposing the cushion mechanism on a part of the drive mechanism are possible for disposing the cushion mechanism.
Incidentally, when the button is attached by the button attaching apparatus, relatively low pressing force is required for the die in caulking claw portion. However, when rivet-bar type or eyelet type button is caulked, relatively high pressing force is necessary. In order to widely respond to the strong caulking force and weak caulking force, weak spring may be used for supporting one of the dies and strong spring may be used for supporting the other dies.
FIG. 4 shows a button attaching apparatus using the two, i.e. strong and weak springs.
The button attaching apparatus 10 has a metal, approximately box-shaped frame 11, the frame 11 having a recessed work portion 12 at a front side thereof. An upper holder 21 (first holder) for supporting an upper die 20 (first die) is located on the upper side of the work portion 12 and a lower holder 31 (second holder) for supporting a lower die 30 (second die) is located on the lower side thereof.
The lower holder 31 is fixed to the frame 11. On the other hand, the upper holder 21 is vertically advanced and retracted by a drive mechanism 40 installed in the frame 11 for a predetermined stroke. The drive mechanism 40 has a motor 41 as a drive source, which pivotably moves a link mechanism 46 through an arm 42, a rod 43, a crank 44 and a rod 45, the pivot movement vertically moving the upper holder 21.
Accordingly, in the button attaching apparatus 10, the upper holder 21 and the lower holder 31 are moved toward and away from each other by driving the drive mechanism 40, so that upper die 20 and the lower die 30 supported by the respective holders are separated and pressed to caulk the button and the backing member respectively held by the dies.
In the button attaching apparatus 10, the upper holder 21 and the drive mechanism 40 for advancing and retracting the upper holder constitute a first side portion and the lower holder 31 disposed on the frame 11 in a fixed manner constitutes a second side portion. An upper cushion mechanism 22 (a first cushion and a first cushion adjuster) are provided on the upper holder 21 included in the first side portion and a lower cushion mechanism 32 (a second cushion and a second cushion adjuster) are provided on the lower holder as the second side portion.
FIG. 5 shows an upper holder 21.
The upper holder 21 has a cylindrical case 210, the case 210 having a hollow section extending from the lower side of the figure to the upper side thereof, the hollow section accommodating a large number of coned disc springs 211 (first cushion), and an end member 212 is disposed on a free end of the coned disc spring 211.
A sleeve 213 is accommodated around the opening of the hollow section of the case 210, and an upper die 20 is attached to the sleeve 213 to prevent detachment by a setscrew 214. The sleeve 213 is abutted to the end member 212 through an adjusting bolt 215 and receives biasing force toward lower side in the figure by the coned disc spring 211. The movement of the sleeve 213 toward the lower side of the figure is restricted by an engaging member 217 projecting into a side opening 216 of the case 210 at a predetermined position. Accordingly, the sleeve 213 can be moved against the biasing force of the coned disc spring 211 when receiving a force in the upper direction in the figure. The adjusting bolt 215 can be rotated to change projection thereof from the sleeve 213, so that initial load applied to the coned disc spring 211 can be increased and decreased, thereby adjusting the biasing force from the coned disc spring 211 to the sleeve 213 (first cushion adjuster).
FIG. 6 shows a lower holder 31.
The lower holder 31 has a cylindrical case 310, the case 310 integrally clamping and fixing a part of the frame 11 and a base 312 along the backside of the frame 11 by screwing a nut 313 to an external screw formed on the outer circumference thereof. A plurality of tie rods 314 are connected to the base 312. A support plate 315 is inserted to an end of the tie rods 314, where an adjusting nut 316 is screwed. A coil spring 317 (second cushion) is disposed coaxially with the case 310 between the support plate 315 and the case 310.
A support rod 301 and a sleeve 302 are coaxially disposed inside the case 310 in an overlapping manner. A flange 303 is formed at the halfway of the sleeve 302, the flange 303 being supported by an upper end (in the figure) of the coil spring 317 and being held while being pressed to the nut 313 by the biasing force in the upper direction in the figure from the coil spring 317. A lower end (in the figure) of the sleeve 302 extends to a central opening of the support plate 315. An internal thread is formed at a distal end of the sleeve 302. An adjusting bolt 305 is screwed to the internal thread. A rotation-stop lock nut 304 is screwed to the adjusting bolt 305. An upper end (in the figure) of the adjusting bolt 305 is abutted to the lower end (in the figure) of the support rod 301. A lower die 30 is attached to an upper end (in the figure) of the case 310. The rotation of the lower die 30 is restricted by a buried screw 311 screwed from a side of the case 310 but is capable of vertical movement in the figure relative to the case 310. An end of the lower die 30 is abutted to the support rod 301 to support the load applied thereto. Accordingly, when the lock nut 304 is loosened and the adjusting bolt 305 is rotated relative to the sleeve 302, the support rod 301 is elevated and lowered relative to the sleeve 302 or the frame 11, so that the position of the lower die 30 relative to the upper die 20 can be adjusted (die position adjuster).
When a force to the lower side of the figure is applied from the lower die 30, the load is transferred to the sleeve 302 through the support rod 301, the adjusting bolt 305 and the nut 304 to press the coil spring 317. When the load is more than a predetermined value, the lower die or the sleeve 302 are moved to the lower side in the figure. The initial load of the coil spring 317 can be increased and decreased by adjusting the position of the support plate 315 by rotating the adjusting nut 316, so that the biasing force applied from the coil spring 317 to the sleeve 302 can be adjusted (second cushion adjuster).
Incidentally, a guard 308 using a weak coil spring 309 is attached around the lower die 30 for preventing fall-off of the buttons etc. before the die touches the fabric.
In the above button attaching apparatus 10, the upper coned disc spring 211 is normally of relatively weak biasing force and the lower coil spring 317 is normally of relatively strong biasing force. Specifically, the weak biasing force of the upper coned disc spring 211 is set for a button capable of being attached with weak caulking force and the strong biasing force of the lower coil spring 317 is set for a button requiring strong caulking force. Accordingly, the coned disc spring 211 or the coil spring 317 is displaced in accordance with the difference in the thickness of each fabric using the same button attaching apparatus 10 either in a case requiring strong caulking force or in a case capable of displacement with a weak caulking force, thereby appropriately attaching the buttons in accordance with characteristics of the respective fabric.
For instance, when a button capable of being attached with a weak caulking force, the button etc. is held respectively on the upper die 20 and the lower die 30 and the upper die 20 and the lower die 30 are moved toward each other to sandwich the fabric disposed on the halfway thereof. At this time, since the caulking force is weak, the coil spring 317 of the lower holder of which biasing force is set strong is not compressed. On the other hand, the coned disc spring 211 of the upper holder 21 of which biasing force is set weak is appropriately compressed to be displaced in accordance with the fabric, thereby appropriately attaching the button.
For attaching a button requiring strong caulking force, the button etc. is held respectively on the upper die 20 and the lower die 30 and the upper die 20 and the lower die 30 are moved closer to sandwich the fabric disposed on the halfway thereof. At this time, a large-diameter upper die 20 (see dotted line in FIG. 5) is used in the upper holder 21 so that outer circumference 20A is abutted not to the sleeve 213 but to the case 210, so that the coned disc spring 211 of weak biasing force is not compressed, thereby allowing strong caulking force. Accordingly, the coil spring 317 of which biasing force is set strong is compressed in the lower holder 31, thereby conducting displacement in accordance with the fabric for appropriate button attaching.
Incidentally, in order to appropriately attach the button in the above-described button attaching apparatus 10, the biasing force of the coned disc spring 211 and the coil spring 317 has to be set at an appropriate value in the upper holder 21 and the lower holder 31.
Additionally, though the fluctuation in the thickness of the fabric can be appropriately dealt with by the above-described cushion mechanism, appropriate caulking force is influenced by the load required for plastic deformation of the button and the backing member and the rigidity of the frame etc. Since the caulking force required for, for instance, snap fastener, amounts to approximately 1000 to 8000N, not only the flexure of the spring but also the flexure of the frame etc. has to be taken into consideration in attaching the button.
Accordingly, the setting of the button attaching apparatus has to be adjusted at least on the initial stage of installation for each button attaching apparatus and the buttons to be attached.
At present, in order to appropriately attach the buttons, 1) adjustment of relative position (bottom dead center position of advancing and retracting crank mechanism etc.) when the upper die and the lower die are brought the closest, and 2) adjustment of cushion mechanism in accordance with the fabric (adjustment of initial load of the coned disc spring 211 by the adjusting bolt 215 and adjustment of initial load by the coil spring 317 by the adjusting nut 316) are considered necessary.
Conventionally, such adjustment is conducted by actually conducting repeated button attaching while the buttons and the backing members are put into the dies and checking finished condition resulted therefrom.
However, in the above method, repeated setting processes and finish checks are required for adjusting the above die position and respective initial load. Especially, since the buttons are actually attached by putting the buttons and backing members into the dies, totally great amount of work is necessary. Further, since the reference thickness of fabric has to be administered for adjusting the cushion mechanism, handling thereof becomes troublesome. Furthermore, since spring constant of the cushion mechanism and rigidity of the mechanical portion of the frame etc. are greatly deviated, reference value setting is difficult, requiring much time and skill for adjustment and making appropriate adjustment difficult.
A primary object of the present invention is to provide an adjusting method and adjusting jig capable of easily and rapidly conducting adjustment required for a button attaching apparatus.